release(7): Add entries for the new mfsBSD build targets

[soobinrho]

Summary

As mfsBSD build targets are integrated into the release tool set, this
commit adds corresponding entries on release.7. The structure and
format of the added entries are based on the entries that are already
there -- e.g. VIRTUAL MACHINE DISK IMAGES. I wanted to make sure they
conform to the pre-existing style and structure as much as possible.

I tested and verified share/man/man7/release.7 as follows:

sh
cd /usr/share/man/man7
man ./release.7

Sponsored by: Google, Inc. (GSoC 2023)
Signed-off-by: Soobin Rho <[e-mail]>

[soobinrho]

Updated the revision diff. (Reverted a wrong eof added by mistake)